In beverage bottling processes, labels and relief-like impressions on bottles, so-called embossings, normally have to be aligned with respect to one another as accurately as possible. As is generally known, this is achieved in that, prior to being labeled, the filled bottles, which are positioned on rotatable centering devices, are brought into a defined initial rotary position; in so doing, the embossings are localized by forming a developed view of the bottle surface in front of a camera unit. However, the positioning of the bottles on the alignment cams of the centering devices as well as the drive means of the centering devices cause inaccuracies, so that it may perhaps not be possible to attach individual labels with the accuracy demanded.
Although known inspection devices for labels, like those described e.g. in DE 20 2005 020 478 U1, EP 0 872 724 A2 and U.S. Pat. No. 4,509,081, allow an imaging examination of the labels in incident light, the embossings, which have comparatively little contrast, cannot be recognized reliably by these devices.